I have a Sun Fire 280R, which uses the same system board as the
Sun Blade 2000 (and the 1000). However, there are some differences
(other than the housing).

The 280R uses drives 0 and 1 internally, while the 2000 uses
drives 1 and 2.

The 1000 has a pair of firewire ports, while the 280R has them
covered by a welded steel cap, and the OS (Solaris 10) does not seem to
notice the ports.

So -- two questions:

1) *Why* is the firewire disabled in the 280R? Just not needed for
the intended purpose of the machine?

2) How does it *know* to disable it?

Does it base it on the drive numbers?

Does it base it on the presenced or absence of the RSC board?

Does it base it on something in the different power cable to the
Fibre Channel drive backplane?

Does it perhaps base it on the presence or absence of a Creator
3D framebuffer? (There are two slots for them on the 280R, but
the primary one does not have a matching opening for the card
bracket, and the secondary one is used by the RSC card.

None of this is really critical to know -- but curiosity prompts
me to ask.

[QUOTE=unix;388119]1) *Why* is the firewire disabled in the 280R? Just not needed for the intended purpose of the machine?[/QUOTE]
Don't know for sure, but this seems most reasonable.

[QUOTE=unix;388119]
2) How does it *know* to disable it?

Does it base it on the drive numbers?
Does it base it on the presenced or absence of the RSC board?
Does it base it on something in the different power cable to the Fibre Channel drive backplane?
Does it perhaps base it on the presence or absence of a Creator 3D framebuffer?

(There are two slots for them on the 280R, but the primary one does not have a matching opening for the card bracket, and the secondary one is used by the RSC card.)[/QUOTE]
Also don't know, but the "conversion switch" between Blade 1000 and Fire 280R is the RSC board.
If you remove the RSC from a 280R it reports as Blade 1000, whereas a Blade 1000 reports as Fire 280R if you put an RSC board in.
I have both machines and tested that. :)
The absence/presence of a framebuffer is not relevant.
A probably important difference is the Power Distribution Board of the Fire 280R with the drive backplane, which is not available on the Blade 1000.
The I2C cable from the RSC connects to this board, which is used for monitoring the temperatures, keyswitch position, FSP LED, disk, fan and power supply information.
One side effect of the "Blade-To-Fire" conversion by adding an RSC is that the fan control does not work anymore. As soon as you boot into Solaris without RSC, the fans go silent.

To make the difference visible:

This is the output of [b]prtdiag -v[/b] on a genuine [I]Fire 280R[/I]:

Summary:
Without the power distribution board you have no environmental monitoring.
It is nice to have an RSC to turn on/off your machine remotely.
But if your ears are in range, the missing fan control is a huge disadvantage.
I'll remove the RSC card until I find a solution for the fans.